Hey man,
welcome to it.
1. I'm not aware of anything coming out in the next few months. What's out is out. Question for you is, what are you going to do with it? If you're doing something with it like audio and video editing, I'd say wait till End of year. But if you're not and you're just doing the basics, go ahead and treat yourself. One thing to remember is, is that the typical Mac is kept and used 4 times as long as a windows box. There are still a few members here who still use G3's and alot use g4's still.
2. Pairing your memory is good. Buying your memory from someone like newegg.com for at least a hundred dollars cheaper is even better. I always tell my customers to just get the bare minimum from Apple, then go ahead, get 2 1gb sticks from newegg or compusa. Pull the one 512mb chip out, put those bad boys in and stick the 512 up on craigslist or ebay. Reasoning is that its WAY cheaper this way to max out your memory.
3. Well. This is the doozie. There are alot of options here. The first thing is to plan out how you want to work. To do that you actually need to have the Mac in frontof you so you can work with it and decide.
So.. let me kind of lay it out for you to see what you like.
Outlook... its one program, huge interface, tons of options, all bundled together. We know it we love it. Ok...
So now on the Mac you have all of those functions but they're split up. There's Mail to handle your mail. Address Book for your contacts. iCal for the calendars and To Do's. The flip side is that Office for the Mac has Word and all that, and Outlook on the Mac is called Entourage. Entourage is outlook rebranded and reworked for Mac. It DOES have one great thing called the Project Center.
From here its all personal taste. I personally use the Mail/ ical / addybook combo. I just seem to like the way that it works better. Added to the fact that I have a Sony w810 cellphone that I can sync up using iSync. (there are plugins for entourage to work with isync but my gut reaction is that they're a bit sloppy)
This link is to MS's tool to import the PST file from Outlook to Entourage. I've used it. it works.
So... Take it for what its worth. I highly respect the MacDev team in Redmond. They do a SUPERB job of making Office. Its just not for me. Others will disagree and thats fine. Its all personal taste. I just think the Mail look looks better to me, more refined. But to each his own.
I would say this as well. Think about what you want to do with your data. Do you want to sync it to a mobile device? What device? Smartphone? Yes you can sync a windows smartphone (oxymoron if there EVER was one!) but it needs extra software to do that. To a Palm? You can do that too. Many phone that hook up via bluetooth or usb will sync. Check the iSync page for the list. Tons of Nokias and Motos and Sony's. I bought myphone specifically so that I could sync my phone lists. I have the total solution. I sync the addy book, ical and to do notes to my phone, and everything just works.
So basically give it a whril and see what you like. There is another proggie out there called Plaxo that will do a sync, but my understanding is that its another program that requires a subscription, and its another layer over outlook / entourage that is just one more layer between you and your data.
And as always, please make a back up copy of your data before you do any of this.
Good luck,
Bishop